1. Cap9. Piston2. Roller boss cap10. Seal, piston3. Roller, the cap11. Pin, dowel, valve4. seal cap12. Valve stop5. seal cap13. Valve slide6. Stud14. Seal, cylinder7. Seal, stud and piston15. Cylinder8. Seal, studFigure 12-57.Liquid spring shock assembly.on the slight compressibility of liquids. Figure 12-57illustrates the disassembled spring assembly. Most ofthe internal parts are classified as nonrepairable, anddamage will require replacement of the parts at the depotlevel of maintenance.The spring assembly contains 19 cubic centimetersof oil, MIL-S-21568. The oil is confined within thepiston cylinder assembly, and any side movement of thearresting hook shank must be against the compressibilityof the oil. The maximum travel or compressibility of theoverall liquid spring assembly is 0.68 inch. Theoperating pressure within the assembly, when bottomedout, will be as high as 20,000 psi. In the static condition,the oil trapped within the spring assembly is under areturn preload pressure of 350 pounds, which is createdby the reassembly of the close tolerance parts thatconfine the liquid.theThe tolerances of parts within the liquid spring andnecessity to subject certain parts to approximately110°F for varying lengths of time during thedisassembly and assembly process make it impracticalfor it to be overhauled at the lower levels of mainte-nance.DAMPER CYLINDER.The representativearresting gear assembly employs a vertical dampercylinder and two horizontal dampers to dampen hookmotion caused by deck impact forces. See figure 12-58.Two centering spring assemblies maintain the hook inthe center position.With the arresting hook lowered, the centeringsprings are adjusted in the following manner:1. Center the hook assembly.12-66